The simple answer is the key is in the name; SAD is seasonal.
Although it may sound simple it can be hard to spot to start with. We often don’t pay much attention to when we feel happy and when we feel low but if, looking back, you realise that your low times always come around the same time of year it’s a hint it may be SAD.
Do you always dread changing the clocks because you know it’s the start of a time where you feel depressed?
Are you always anxious in February?
Do you find that when the sun comes out you seem to get so much more done than on a dreary dark day?
If you said yes to any or all of these questions it’s possible you have SAD.
Take a look at the common symptoms to see if they sound familiar.